Verfahren zur kontinuierlichen Herstellung von Polybutylenterephthalat aus Terephthalsäure und Butandiol

摘要

The invention relates to a method for the continuous production of polybutyleneterephthalate from terephthalic acid and 1,4-butanediol, comprising the following: d) the direct esterification of terephthalic acid with 1,4-butanediol in a reactor series consisting of at least two reactors; e) the precondensation of the product of esterification obtained in step a); f) the polycondensation of the precondensate obtained in step b). The reactor series in step a) is operated with a falling reaction pressure and a non-rising temperature.